Ba’t is the short form of the question word Bakit.

This shortened form Ba’t is never used alone. There has to be some other word after it.

Bakit ganito?
= Ba’t ganito?
Why like this?

Bakit ka nandito?
= Ba’t ka nandito?
Why are you here?

Translation of the English word “bat” ?

a club or stick used to hit something or someone

a fruit bat

Note that the Tagalog word kabag has another unrelated meaning, which is flatulence or gas in the intestines.

a bat like the one associated with Batman